Studies On The Pathology And Histochemistry Of European Eel (Anguilla Anguilla) With Septicemia

European eel (Anguilla anguilla) has been extensively cultured and becoming an important aquaculture industry recent years in our country. With the rapid development and intensive culture, however, many kinds of diseases occurred frequently, causing massive mortalities and economic losses. The septicemia is the worst among all the diseases. According to the investigation recently, we found that the morbidity and mortality of septicemia all went up. The study was conducted in order to maintain the sustainable development for the industry. From heancyte, pathological and histochemistrial changes, the pathological process of the syndrome was discussed.Herpesvirus particles were detected from gill, liver and intestines of diseased European eels by electron micrographs. Virions were round shapes, about 80nm-100nm in diameter, which have three type, double-enveloped, an electron-light core or an electron-dense core.The blood changes of the of European eel septicemia showed that the erythrocyte rate dropped and erythrocytes dissolved, the number of leucocytes and the osmotic fragility remarkable increased, the different leucocytes count (DLC) and the shape of blood cell changed, which was the results of the pathogens that had a hemolytic function.From the pathological observation of the gill, heart, kidney, liver, spleen and intestine of European eel with septicemia, we found that gill cells show swelling, changing, coming off, gill's structure broke down and some merged to the form of club. The cardiac muscle fibrous swelled, twisted rupturing, arranged disorderly, the interval of muscle fiber was increased widely, the membrane of the heart ruptured. Liver cells swelled and necrotized widely, it became on-structure uniform substances in the end and the renal tubule epidermis cells necrotized. The spleen was remarkably broken and obviously filled with erythrocyte. Spleen netting cells, the white structure was destroyed. Hemopoietic tissues and instructed connective tissue necrotized a lot and turned into a pink and non-structure substance. As seriously hemolytic there were more blood segments in the spleen, it could be colored brown yellow by H.E. Skin cells broke away from the intestines, the blood cells were soaked. The renal corpuscle expanded cavity in the kidney. Renal tubule epidermis cells necrotized, fracted and renal corpuscles became less.The organism ultrastructure pathology changes were characterized by the nucleus dissolved and organdie vanished in gill cells. The structure of myocardial disappeared, nucleolus dilated and mitochondrion vacuole. Hepatocyte obviously was destroyed, the outer nucleus membrane was rupturing and light chromatin, organelle disappeared, lipid dropts stepped up and irregularly compacted in liver. In abnormal spleen, nucleus deformed and the number of macrophage increased, cytoplasm was sparse and the outer membrane of nucleus disintegrated, mitochondrion degenerated and necrosis endoplasmic reticulum disordered and ribosome fell off, the number of lysosome and remains increased in cytoplasm. The epithelia cells fragmented in intestines microvillus irregularly arranged, mitochondrion seriously dilated and disintegrated, microvillus arranged disorderly and broke away. The endothelial cell of capillary vessel dilated and broke in abnormal renal corpuscle, epithelia cells fused with each other and were microvillus: organelle disappeared, mitochondrion seriously vacuole in cytoplasm.We used the histochemistry method to discuss the distribution and change situation of the alkalinep hosphatase (ALP) and the acid phosphatase (ACP) in the European eel with septicaemia. The result showed: the cell wall was broken, the alkalinep hosphalase and the acid phosphatase were piled up the epithelia cell, which deducted that themembrane structure damaged, broken and incompleted.The viscera of European eel with septicemia had denaturalized pathological changes seriously. Histopathology changes were mainly hemolytic anemia and tissue cells denaturalizing and necrotizing widely. A lot of endothelial swelled and fracted with nucleus dotting. The pathogens of European eel with septicemia caused hemolytic intensively and whole -body-tissue damaged, all organs tissues swelled, denaturalized with a granule and blister, necrotized and disintegrated by invading the liver, kidney, spleen, gill, intestine, heart, muscle and bloods, even erythrocyte fracted and dissolved hemolytic amiemia in the end. Whether the skin or the viscera of the diseased, European eel with septicemia were founded hemolytic intensively and widely, even ulcer and erosion. As hemolytic and noxias of the diseased, blood circle, respiration, digestive and excreting mechanism can't work, in the end leading to death with crocking up.